1. Field of the Invention
The present invention relates to a method and equipment for semiconductor processing, and to a semiconductor processing equipment module, especially for cleaning semiconductor wafers to achieve a total system which provides high efficiency FA (factory automation).
2. Description of the Related Art
FIG. 25 is a schematic diagram showing the structure of conventional semiconductor processing equipment such as (semiconductor) wafer cleaning equipment. In this figure, one or more wafer cassettes (not shown) are carried from the outside into wafer cleaning equipment 1 via a loader 2. A wafer taking-out unit 3 takes out only wafers (not shown) from the carried-in wafer cassettes. These wafers are wet-cleaned in a wafer cleaning bath 4. After the cleaning, a wafer inserting unit 5 inserts the wafers into a cassette containing no wafer in it (not shown, described as a vacant cassette hereafter). In the processing, a wafer carrying robot 7 holds wafers taken out by the above wafer taking-out unit 3, and carries them into the wafer cleaning bath 4. Furthermore, after the wafers are cleaned, the wafer carrying robot 7 carries the wafers to the wafer inserting unit 5. Cassettes containing cleaned wafers (not shown) are carried out of the wafer cleaning equipment 1 via an unloader 6.
The operation of a conventional wafer cleaning equipment having the structure shown above is described next. As shown in FIG. 13, when one through four product cassettes containing wafers to be cleaned are placed in the loader 2, the wafer taking-out unit 3 separates the wafers from the cassettes. Then, the wafers are carried to the cleaning bath 4 by the wafer carrying robot 7. The cassettes which became vacant are carried out of the wafer cleaning equipment 1 via the loader 2.
After the wafers are cleaned in the cleaning bath 4, the wafers are carried to the wafer inserting unit 5 by the wafer carrying robot 7. Then, the wafer inserting unit 5 inserts the wafers into vacant cassettes which are placed in an unloader 6 in advance. After that, the product cassettes containing the cleaned wafers are carried out of the wafer cleaning equipment 1 via the unloader 6.
The wafer cleaning equipment described above has a very limited function that it takes wafers out of product cassettes, performs wet cleaning for wafers, and inserts wafers back into product cassettes. As a result, further operations have to be performed at a certain place outside of the wafer cleaning equipment to remove and keep ID cards attached to product cassettes before wafers are carried into the wafer cleaning equipment. Moreover, it is also necessary, at a place outside the wafer cleaning equipment, to attach corresponding ID cards to product cassettes carried out of the wafer cleaning equipment after the wafers are cleaned. This prevents achievement of full factory automation (described by FFA hereafter) by robots.
Furthermore, in conventional wafer cleaning equipment, carrying products into the equipment and placing them into a cleaning bath are carried out on one same side of the equipment, but carrying products out STET the cleaning bath is done on the other side of the equipment. Therefore, to carry products in/out a cleaning bath, there must be plural carrying robots such as robots for carrying products into equipment before cleaning, robots for carrying products out of the equipment after cleaning, and robots for carrying vacant product cases from a location via which products to be cleaned are put into equipment to a location via which cleaned products are carried out. This gives rise to problems such as high costs for FA or large areas occupied by robots in clean rooms.